Guaiazulene, namely 1,4-dimethyl-7-isoproylazulene, is an active ingredient of Chrysanthemum plants, which has a structural formula as follows:

Guaiazulene has strong effect of anti pepsin, anti-inflammatory, anti-allergic and promoting mucosal metabolism. Its many derivatives also exhibit excellent biological activity. Compound Guaiazulene Ointment (Shanxi Tongsheng Pharmaceutical Co., Ltd.) can be used for burns, scalds, scorches, frostbite, chap, decubitus, radiation heat, dermatitis and etc.
Since the excellent pharmacological activities of guaiazulene, there have been many studies on structural modification of Guaiazulene. The resultant derivatives include azulene sodium sulphonate, 3-(2-substituted thiazole-4-yl) guaiazulene, 1-(2-benzofuran acyl) guaiazulene and etc. Among which, azulene sodium sulphonate is a water-soluble derivative of guaiazulene, has excellent anti-inflammatory and wound healing properties, and is used as the main ingredient of the currently available drug Glutamine Granules for treating gastric ulcer. Azulene sodium sulphonate can directly act on the inflammatory mucosa and has better therapeutic effect on various gastritis, as well as complications of gastritis and ulcers.
However, it is found by experiments that azulene sodium sulphonate has some stability issues, especially poor light stability and heat stability. In order to ensure the safety of products, the cost of product storage and transportation must be increased to prevent decomposition of the active ingredient and generation of impurities, leading to increased production costs.
Currently, there is no report about structural modification to improve the stability of azulene sodium sulphonate.